I don't know where you live, but if it's the UK, and you are not a million miles from Slough, I would take it in to Pentax and see if someone there is prepared to discuss the problem with you and take a look at the camera.

I once had the screws come loose on a lens, and took it in personally. They fixed it while I waited, and made no charge. It wasn't under guarantee.

This was a while ago, but it might be worth a shot. It's conceivable there's a little potentiometer somewhere that just needs half a turn, and bingo.

But I'd certainly go to Pentax themselves (for this kind of problem), rather than an independent. Lenses and older cameras are another matter.

Another thing I didn't mention, though it is unlikely to apply to a new camera, is that dirt on the lens mount contacts (on both body and camera) can result in the camera receiving false information about the lens. These need to be kept clean.

G

How often does one have to say it? If it isn't working, take it back to the shop.

There are lots of highly competent photographers (as well as me) using these cameras without problems. Either you are doing something wrong, or there is a fault.

Some considerations:

Have you turned off Sensitivity Correction?
Have you linked AF point and AE? (Good idea for portraits, etc)
Are you using matrix metering? (Works best with modern lenses)
Have you set focus point to centre? (Avoids all sorts of problems)
Have you set ISO to 200?
Are you using third party lenses? (Some lens chips are incompatible -especially Sigma's)
What exposure mode are you using?
Is the lens set to "A"?
What is the program line set to?

Remember that if something works, it's not news. The people who post to message boards with problems are not a representative selection of users. Modern cameras are complex, and sometimes people don't understand the significance of all the settings. Do you know the significance of all the above, and are you using Pentax lenses?

If you are confident you are using the camera properly, and still have problems, then take it back and ask for one that works. I am active on more than one dedicated Pentax list, (not general forums like DP Review) and there is definitely not a general problem with Pentax DSLRs. However, a few owners have had faulty cameras.

And don't pay too much attention to reviewers, who have a camera for a few hours and claim to be experts on it. They are frequently biased towards their own favourite make, and many accept "gifts" of free equipment from manufacturers. It's a wicked world.

Interesting.

I have 100mm 2.8 lenses in both M and FA macro versions, and 28mm 2.8 in both M and F.

I have placed the camera (*ist D) on a tripod in the kitchen, and shot with all four lenses using ambient light on manual with the aperture set on f5.6 on the lens. I then pressed the green button to set the exposure.

These are the recorded shutter speeds:

M 28 1/3.3
F 28 1/5 (Definitely looks slightly under-exposed)
M 100 1/2
FA 100 1/3.3


I was using spot metering, so I tried again with matrix, but pointing in a different direction, with less light:

M 28 1/8
F 28 1/10
M 100 1/5
FA 100 1/10

and finally with centre-weighted:

M 28 1/8
F 28 1/10
M 100 1/6
FA 100 1/13 definitely under-exposed

All exposures were acceptable (except for the two marked otherwise), though always slightly on the under-exposed side. This is perhaps understandable given the preponderance of bright white surfaces in the kitchen.

So from this brief test it seems that the camera tends to under-expose more with AF lenses than with M lenses. This is completely opposite from JR's experience.

I have to say that in practice I haven't been conscious of any exposure problens, though I do always adjust levels in the computer. I usually shoot Jpeg and I usually use Irfanview for adjustments (because it's so quick), unless the picture requires the extra muscle of Photoshop.

G

Either you are doing something wrong, or you have a faulty camera. Take it back to where you got it from, and ask them to fix or replace it.

There's nothing anybody here can do to help you, other than to advise you to check that you are doing everything correctly.

G

Sorry, John. I must be going blind. Probably because the 50mm is the only focal length I've heard of, apart from 85mm, that has a 1.4 version.

G

http://www.bdimitrov.de/kmp/lenses/primes/normal/M50f1.4.html

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=80441&item=3867...

It's also on Stan's site.

Unfortunately, I bought my ME in New Orleans when they first came out, in 1976, and at that time only the f1.7 was available. It would have been nice to have had a 1.4.

George

If you're a DIY fanatic, I have heard of people with more courage than money scraping off the sticky mess themselves, and replacing the rubber with strips taken from washing up gloves and other similar articles.

Up to you..........

G

Your zoom lens has a variable maximum aperture, which is why two numbers are quoted. At the short end of the zoom range, the max aperture is f3.5. At the long end it is f5.6. Somwhere in between, it might be f4.

With F stops, the lower the number, the larger the aperture. F4 lets in twice as much light as f5.6.

Full F stops are the numbers I listed. However, many lenses have indents mid-way between the full stops to give half stops. Some camera/lens combinations use one third stops. F3.5 and f13.5 are half stops.

It's a pity the people who designed lenses didn't come up with a simple linear scale, where a higher number equals a larger aperture. But, they didn't.

Just remember that shutter speeds and apertures are complementary, and each is half or double the previous one. So, if you increase the F number by one stop, and reduce speed by one click on the speed dial, you will still have have the same exposure value (ie: the same amount of light passes thrrough the lens).

I suspect that when you were playing around with your lens, you didn't have much light. Point the lens at a bright light source, with a slower shutter speed, and you'll soon see f11 and f16.

G

Fiannor,

Aperture is always expressed as an "F" number, as in "f3.5". Don't ask me why, but that is the convention. I was referring to apertures, not focussing.

You will soon recognise the numbers. In full, they are: f1, f1.4, f2, f2.8, f4, f5.6, f8, f11, f16, f22 and f32. Note how every number is double the previous number but one.

You'll never find an f1 lens on an SLR.

DOF stands for "depth of field".

If I were you, I would leave focus on auto at the moment, until you have mastered the relationship between apertures and shutter speeds, and the effect of aperture on DOF.

If you need to focus on something which isn't in the centre of the viewfinder, point the camera at whatever it is, depress the shutter button half-way, which will cause the camera to focus the lens but not to trip the shutter.

Then frame your shot, keeping the button part depressed (which locks the focus), and press harder to take the picture.

You'll get it eventually!

Incidentally, there is nothing clever or professional about using manual focus. All pro cameras are autofocus because most of the time, AF is quicker than focussing manually.

G